const std = @import("std");
const cbor = @import("cbor");
const tp = @import("thespian");
const root = @import("soft_root").root;
const command = @import("command");
const Buffer = @import("Buffer");
const builtin = @import("builtin");
const CompletionItemKind = @import("lsp_types").CompletionItemKind;

const tui = @import("../../tui.zig");
pub const Type = @import("palette.zig").Create(@This());
const ed = @import("../../editor.zig");
const module_name = @typeName(@This());
const Widget = @import("../../Widget.zig");

const Values = @import("completion_dropdown.zig").Values;
const get_values = @import("completion_dropdown.zig").get_values;
const get_replace_selection = @import("completion_dropdown.zig").get_replace_selection;

pub const label = "Select completion";
pub const name = "completion";
pub const description = "completions";
pub const icon = "󱎸  ";
pub const modal_dim = false;
pub const placement = .top_right;

pub const Entry = struct {
    label: []const u8,
    sort_text: []const u8,
    cbor: []const u8,
};

pub const ValueType = struct {
    start: ed.CurSel = .{},
    replace: ?Buffer.Selection = null,
};
pub const defaultValue: ValueType = .{};

var max_description: usize = 0;

pub fn load_entries(palette: *Type) !usize {
    max_description = 0;
    var max_label_len: usize = 0;

    var existing: std.StringHashMapUnmanaged(void) = .empty;
    defer existing.deinit(palette.allocator);

    const editor = tui.get_active_editor() orelse return error.NotFound;
    palette.value.start = editor.get_primary().*;
    var iter: []const u8 = editor.completions.data.items;
    while (iter.len > 0) {
        var cbor_item: []const u8 = undefined;
        if (!try cbor.matchValue(&iter, cbor.extract_cbor(&cbor_item))) return error.BadCompletion;
        const values = get_values(cbor_item);

        const dup_text = if (values.sort_text.len > 0) values.sort_text else values.label;
        if (existing.contains(dup_text)) continue;
        try existing.put(palette.allocator, dup_text, {});

        if (palette.value.replace == null) if (get_replace_selection(editor, values)) |replace| {
            palette.value.replace = replace;
        };
        const item = (try palette.entries.addOne(palette.allocator));
        item.* = .{
            .cbor = cbor_item,
            .label = values.label,
            .sort_text = values.sort_text,
        };

        var lines = std.mem.splitScalar(u8, values.label_description, '\n');
        const label_description_len = if (lines.next()) |desc| desc.len else values.label_description.len;

        max_label_len = @max(max_label_len, item.label.len);
        max_description = @max(max_description, label_description_len + values.label_detail.len);
    }

    const less_fn = struct {
        fn less_fn(_: void, lhs: Entry, rhs: Entry) bool {
            const lhs_str = if (lhs.sort_text.len > 0) lhs.sort_text else lhs.label;
            const rhs_str = if (rhs.sort_text.len > 0) rhs.sort_text else rhs.label;
            return std.mem.order(u8, lhs_str, rhs_str) == .lt;
        }
    }.less_fn;
    std.mem.sort(Entry, palette.entries.items, {}, less_fn);

    max_description = @min(max_description, tui.screen().w -| max_label_len -| 10);
    return @max(max_description, if (max_label_len > label.len + 3) 0 else label.len + 3 - max_label_len);
}

pub fn initial_query(palette: *Type, allocator: std.mem.Allocator) error{OutOfMemory}![]const u8 {
    return if (palette.value.replace) |replace| blk: {
        const editor = tui.get_active_editor() orelse break :blk allocator.dupe(u8, "");
        const sel: Buffer.Selection = .{ .begin = replace.begin, .end = palette.value.start.cursor };
        break :blk editor.get_selection(sel, allocator) catch break :blk allocator.dupe(u8, "");
    } else allocator.dupe(u8, "");
}

pub fn clear_entries(palette: *Type) void {
    palette.entries.clearRetainingCapacity();
}

pub fn add_menu_entry(palette: *Type, entry: *Entry, matches: ?[]const usize) !void {
    var value: std.Io.Writer.Allocating = .init(palette.allocator);
    defer value.deinit();
    const writer = &value.writer;
    try writer.writeAll(entry.cbor);
    try cbor.writeValue(writer, matches orelse &[_]usize{});
    try palette.menu.add_item_with_handler(value.written(), select);
    palette.items += 1;
}

pub fn on_render_menu(_: *Type, button: *Type.ButtonType, theme: *const Widget.Theme, selected: bool) bool {
    var item_cbor: []const u8 = undefined;
    var matches_cbor: []const u8 = undefined;

    var iter = button.opts.label;
    if (!(cbor.matchValue(&iter, cbor.extract_cbor(&item_cbor)) catch false)) return false;
    if (!(cbor.matchValue(&iter, cbor.extract_cbor(&matches_cbor)) catch false)) return false;

    const values = get_values(item_cbor);
    const icon_: []const u8 = values.kind.icon();
    const color: u24 = 0x0;

    return tui.render_symbol(
        &button.plane,
        values.label,
        icon_,
        color,
        values.label_detail,
        values.label_description,
        matches_cbor,
        button.active,
        selected,
        button.hover,
        theme,
        &.{},
        &.{},
        &.{},
    );
}

pub fn complete(palette: *Type, _: ?*Type.ButtonType) !void {
    palette.menu.activate_selected();
}

fn select(menu: **Type.MenuType, button: *Type.ButtonType, _: Type.Pos) void {
    const values = get_values(button.opts.label);
    const editor = tui.get_active_editor() orelse return;
    const text = if (values.insertText.len > 0)
        values.insertText
    else if (values.textEdit_newText.len > 0)
        values.textEdit_newText
    else
        values.label;
    editor.insert_completion(null, text, values.insertTextFormat) catch |e| menu.*.opts.ctx.logger.err(module_name, e);
    const mv = tui.mainview() orelse return;
    mv.cancel_info_content() catch {};
    tp.self_pid().send(.{ "cmd", "exit_overlay_mode" }) catch |e| menu.*.opts.ctx.logger.err(module_name, e);
}

pub fn updated(palette: *Type, button_: ?*Type.ButtonType) !void {
    const button = button_ orelse return cancel(palette);
    const values = get_values(button.opts.label);
    const editor = tui.get_active_editor() orelse return error.NotFound;
    editor.get_primary().selection = get_replace_selection(editor, values);

    const mv = tui.mainview() orelse return;
    try mv.set_info_content(values.label, .replace);
    try mv.set_info_content(" ", .append); // blank line
    try mv.set_info_content(values.detail, .append);
    if (builtin.mode == .Debug) {
        try mv.set_info_content("newText:", .append); // blank line
        try mv.set_info_content(values.textEdit_newText, .append);
        try mv.set_info_content("insertText:", .append); // blank line
        try mv.set_info_content(values.insertText, .append);
    }
    try mv.set_info_content(" ", .append); // blank line
    try mv.set_info_content(values.documentation, .append);
}

pub fn cancel(palette: *Type) !void {
    const editor = tui.get_active_editor() orelse return;
    editor.get_primary().selection = palette.value.start.selection;
    const mv = tui.mainview() orelse return;
    mv.cancel_info_content() catch {};
}